Clear channel assessment (CCA for short) adjustment is a hot topic currently researched in the IEEE 802.11ax standard. On an unlicensed spectrum, before sending data, a station needs to first detect a channel status. When a detected power is greater than a CCA threshold, it is determined that a channel is in a busy state, and data sending is not allowed. Conversely, when the detected power is less than or equal to the CCA threshold, the station may perform backoff. After the backoff ends, the station sends the data.
Increasing the CCA threshold enables the station to further perform the backoff without being affected by an interfering signal within a range that is greater than an original CCA threshold and less than an adjusted CCA threshold, so that a probability of spatial reuse may be increased. Emulation proves that increasing the CCA threshold within a certain range may increase throughput of a system, and the range that may be increased depends on a specific application scenario.
Mediatek proposes a method for associating the CCA threshold with transmission bandwidth, so as to increase a probability of accessing a channel by a station. However, in the solution proposed by Mediatek, in some scenarios, the station cannot use a power spectral density as large as possible to send data, that is, a received signal-to-noise ratio of a receiving station is not maximized. Therefore, transmission efficiency of a system cannot be maximized.